As environmental agencies become more aware of the potential health risks associated with drinking either municipal or well water, there has been an ever increasing need for residential water purification systems which are capable of removing organics, inorganics, particulates, microorganisms, bacteria and viruses from the water supply prior to consumption. Most conventional systems require a series of filtration and chlorification units to properly remove such matters from the water. These units are extremely costs to install and maintain, and take up a lot of space making them unfit for countertop use.
Filtration media has been used for years to remove particulates from the water supply, while carbon block filters have been effective in removal of organics and inorganics. However, conventional filters are incapable of removing microorganisms such as bacteria, viruses, yeasts or molds. Ultraviolet radiation in the 200-300 nanometer range have bee_n extremely effective in killing such microorganisms. As such, germicidal lamps have been used extensively in air and water purification, sewage treatment, protection of food and beverages, and other disinfection and sterilization applications.
Recent efforts by filtration manufacturers have resulted in the creation of a water purification system which combines the disinfection and sterilization capabilities of ultraviolet radiation with the particulate, organic and inorganic filtering capabilities of conventional filter media. This combined system provides extremely pure and sterilized drinking water regardless of the origin of the water source.
These conventional two stage water purification systems typically include an ultraviolet lamp affixed to the base unit-of a filtration housing assembly and protected by a stainless steel sheath or sleeve. A conventional carbon block filter is removably slid over the outside of the sleeve and then the filter housing is placed over the carbon filter and screwed into the base. Typically, the ultraviolet lamp is placed within a quartz tube and replaceable mounted to the base.
Two stage water purification systems as discussed above require periodic maintenance such as replacing the carbon block filter approximately every six months (more frequently if needed), replacing the ultraviolet lamp every twelve months to insure proper performance (i.e., lamp may:not burn-out, but disinfection capacity does diminish over time), and quartz tube should be cleaned every six months. Although the carbon block filter is easy to replace, i.e., simply unscrew the filter housing and slide the filter off the stainless steel sleeve at the open end, replacement of the ultraviolet lamp requires substantial disassembly of the base unit of the housing. Since the ultraviolet lamp replacement is extremely difficult, many end-users (i.e., homeowners) will tend to not replace such lamps as frequently as necessary. If the lamp is not replaced on a periodic basis its effectiveness in disinfecting and sterilizing water will diminish over time, thus posing a health risk to unwary end-users.
Therefore, it would be highly desirable to have a two stage water purification system which allows for easy removal and replacement of both the filter and the ultraviolet lamp. In this regard, the present inventor has developed a unique replaceable integrated filtration/sterilization cartridge which is readily and easily removable from the filter housing assembly. This integrated filtration/sterilization cartridge comprises both the ultraviolet lamp and filter member together as one single unit which may be removed from the base unit of the housing assembly without the need for any tools or detailed instructions. Moreover, the concept of combining the filter member and the ultraviolet lamp in a single replaceable cartridge will cause the unsophisticated homeowner or end-use to replace both elements at the same time, thereby avoiding the inherent health risks of leaving a still illuminating, but less effective, ultraviolet lamp within the filter assembly.
The present invention also provides many additional advantages which shall become apparent as described below.